Solve Persistent Electrical Problems in Your GM Truck
If you’re dealing with baffling electrical issues in your 2013 GMC Sierra 3500 or another compatible GM vehicle, a failing Body Control Module (BCM) is often the culprit. As the central command for your truck’s body electronics, a faulty BCM can cause a cascade of frustrating problems, from flickering lights and a dead HVAC system to security lockouts that leave you stranded. This replacement module, part number 20939137, is the definitive solution. Through our professional cloning service, we transfer the essential data from your original unit to this replacement, ensuring a seamless, plug-and-play installation without requiring a costly trip to the dealership for programming.
A Technician’s Notebook: The Grounding Gremlin
I once had a 2011 Silverado 2500 in the bay that was driving the owner crazy. The radio would cut out, the power locks worked intermittently, and the dash would light up like a Christmas tree at random. He had already replaced the battery and checked the alternator. After scanning, I found a slew of communication DTCs pointing to the BCM. Before condemning the module, I went straight to the main BCM ground point under the driver’s side A-pillar kick panel. Sure enough, it was corroded and loose. While in many cases the BCM itself is the failure, I’ve seen hundreds of these GMT900-platform trucks where a poor ground connection was the root cause or a contributing factor. My advice: Whenever you replace a BCM, always take five extra minutes to clean and tighten the associated ground connections. It’s the best preventative maintenance you can do to protect your new module.
Is Your Truck Showing These Symptoms?
- ✔ The security or anti-theft system malfunctions, causing no-start or stalling conditions.
- ✔ Power windows, door locks, or interior/exterior lights operate erratically or not at all.
- ✔ The HVAC blower motor or climate controls are non-responsive.
- ✔ An airbag warning light is illuminated, often with a DTC like B1001 (Setup SDM Primary Key in BCM).
- ✔ The vehicle sets various communication or body-related diagnostic trouble codes (DTCs).
- ✔ Wipers or other accessories activate on their own or fail to turn on.
This replacement 2013 Sierra 3500 Pickup Body Control Module is engineered to restore full functionality and reliability to your vehicle’s essential systems. Our cloning service makes the repair process straightforward for both professional technicians and DIY enthusiasts.
Your 5-Minute BCM Swap Guide
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- ✔ Locate the BCM: On most compatible models, the BCM is located under the driver’s side of the dashboard, near the steering column. You may need to remove a lower dash panel for access.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old BCM. They have locking tabs that need to be depressed. Once disconnected, unclip or unbolt the module from its mounting bracket.
- ✔ Install the New Module: Connect the electrical harnesses to your new, cloned BCM. The connectors are color-coded and keyed to prevent mistakes. Secure the module back onto its bracket.
Will This Fit My Truck or SUV?
This module is a direct replacement for part number 20939137 and is interchangeable with numerous other GM part numbers, including 25844480, 25835966, 15943678, and 22860591. It is confirmed to fit a wide range of 2007-2013 General Motors trucks and SUVs. Please verify your vehicle is on the list below.
Frequently Asked Questions
Frequently Asked Questions
What exactly is a “Cloning Service”?
Our cloning service involves transferring the vehicle-specific software and security data from your original BCM to this replacement unit. This ensures it works seamlessly with your truck’s existing keys, options, and other modules, eliminating the need for dealership programming.
Do I need to send you my original BCM?
Yes. For the cloning process to be successful, you must send us your original, faulty module after you place your order. We will perform the service and ship both your original and the ready-to-install replacement back to you.
Is there a core charge for this part?
No, there is no core charge. We always return your original module along with the newly programmed replacement, so you can keep it or dispose of it as you wish.
My airbag light came on after installation. What should I do?
This is a common occurrence. If the airbag light is on, it means the BCM needs to be synchronized with the airbag system’s Sensing and Diagnostic Module (SDM). A professional scan tool is required to perform the “Setup SDM Primary Key in BCM” procedure. This is a simple relearn function that takes only a minute.
Are any other procedures needed after installation?
In some cases, a Brake Pedal Position (BPP) sensor relearn may be necessary to ensure proper brake light and stability control function. This also requires a capable diagnostic scan tool. Always consult a service manual for procedures specific to your vehicle.